From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
The epoll function expects that whenever the poll file op is
called, the poll_wait function is also called. That didn't
always happen in v4l2_m2m_poll(). Fix this, otherwise
epoll() would timeout when it shouldn't.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-mem2mem.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 631f4e2aa942..d97781b8ff88 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -617,20 +617,22 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
__poll_t rc = 0;
unsigned long flags;
+ src_q = v4l2_m2m_get_src_vq(m2m_ctx);
+ dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
+
+ poll_wait(file, &src_q->done_wq, wait);
+ poll_wait(file, &dst_q->done_wq, wait);
+
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
struct v4l2_fh *fh = file->private_data;
+ poll_wait(file, &fh->wait, wait);
if (v4l2_event_pending(fh))
rc = EPOLLPRI;
- else if (req_events & EPOLLPRI)
- poll_wait(file, &fh->wait, wait);
if (!(req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM)))
return rc;
}
- src_q = v4l2_m2m_get_src_vq(m2m_ctx);
- dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
-
/*
* There has to be at least one buffer queued on each queued_list, which
* means either in driver already or waiting for driver to claim it
@@ -642,11 +644,6 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
goto end;
}
- spin_lock_irqsave(&src_q->done_lock, flags);
- if (list_empty(&src_q->done_list))
- poll_wait(file, &src_q->done_wq, wait);
- spin_unlock_irqrestore(&src_q->done_lock, flags);
-
spin_lock_irqsave(&dst_q->done_lock, flags);
if (list_empty(&dst_q->done_list)) {
/*
@@ -657,8 +654,6 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
spin_unlock_irqrestore(&dst_q->done_lock, flags);
return rc | EPOLLIN | EPOLLRDNORM;
}
-
- poll_wait(file, &dst_q->done_wq, wait);
}
spin_unlock_irqrestore(&dst_q->done_lock, flags);
--
2.20.1
